Interceptive orthodontic treatment need among children attending dental clinics in the Tygerberg sub-district.

Interceptive orthodontic treatment need among children attending dental clinics in the Tygerberg sub-district. A mini-thesis submitted in partial fulfilment of the requirements for the degree of MSc in Paediatric Dentistry, University of the Western-Cape Amanda Karien Marais (BChD) Student nr: 2382354 October 2013 Research was funded by the MRC Supervisor: Dr. A. Hudson Co-supervisor: Dr. N. Mohamed

Interceptive orthodontic treatment need among children attending dental clinics in the Tygerberg sub-district. i

Keywords Children Habits Thumbsucking Functional interferences Mechanical interferences Dental development Dental age Early loss of primary teeth Malocclusion Interceptive orthodontic treatment need ii

Abstract Background In the Western-Cape province, orthodontic treatment provided to government patients is limited to tertiary hospitals such as the Tygerberg Oral Health Centre (TOHC). This results in growing waiting lists which place a huge strain on resources of the facility. Objectives To determine: 1. The prevalence of malocclusion among 7-to-10-year-old children examined at dental clinics within the Tygerberg sub-district. 2. The types of malocclusion they present with. 3. Which of these malocclusions can be treated with interceptive orthodontic treatment. Methods An analytical, descriptive, cross-sectional study was carried out and quantitative methods were used to achieve the aim and objectives. The study sample consisted of 100 children, 46 male and 54 female, from Bellville and Bishop Lavis dental clinics. Dental examinations were done by one examiner on children between the ages of 7 and 10 years. Dental problems were identified which, if left untreated, could result in the need for more complex orthodontic treatment at a later stage. All the necessary ethical clearance was obtained. Results The results showed that there is a very large interceptive orthodontic treatment need (79%) at these clinics. A large proportion (70%) presented with detrimental habits. Thumbsucking was more prevalent among girls than boys. Other problems like mouthbreathing, lip wedging, deep bite, asymmetrical mobility of primary teeth, rotated lateral incisors and crossbites were found. The biggest concern was that 71% of the children had early loss of primary teeth and only 5% of children received restorations, resulting in a high prevalence of unfavourable molar relationships. All of these should be addressed early, thereby preventing the development of complex orthodontic problems or skeletal discrepancies. iii

Conclusion Interceptive and preventive orthodontic treatment should be regarded as a primary health centre service, as it may reduce the need for costly fixed orthodontic treatment. The study showed that urgent intervention is necessary from the Department of Health to address this issue. iv

Declaration I hereby declare that Interceptive orthodontic treatment need among children attending dental clinics in the Tygerberg sub-district is my own work, that it has not been submitted before for any degree or examination at any university, and that all the sources I have used or quoted have been indicated and acknowledged by complete references. Amanda Karien Marais January 2014 Signed: v

Acknowledgements I would like to thank God for helping me and providing me with the opportunity to be able to do post-graduate studies and learn from the experience. Secondly, I wish to thank my husband, Izak and the rest of my family and friends for supporting and loving me. My sincere gratitude goes to both my supervisors, Dr Hudson and Dr Mohamed, for putting in so much effort and time, in helping and guiding me to produce this thesis. I also wish to thank Prof Maritz and everyone involved in helping me with the statistics. I am very thankful to the Medical Research Council (MRC) for providing me with the scholarship to conduct the research. vi

Table of Contents Title page... i Keywords... ii Abstract... iii Declaration... v Acknowledgements... vi List of tables... x List of figures... xi List of abbreviations... xii List of addenda... xiii CHAPTER 1:... 1 INTRODUCTION... 1 LITERATURE REVIEW... 2 1.1 Definitions... 2 1.2 Orthodontic treatment need: studies within South Africa... 2 1.3 Normal dental development... 4 1.4 Molar relationship... 6 1.5 Dental manifestations that can be addressed with interceptive orthodontic treatment... 7 1.5.1 Habits... 7 1.5.2 Interferences... 9 1.5.3 Problems hampering normal dental development... 12 1.5.4 Skeletal discrepancies... 14 CHAPTER 2: MATERIALS AND METHODS... 16 2.1 Aims... 16 2.2 Objectives... 16 vii

2.3 Ethics... 16 2.4 Study sample.... 16 2.5 Research design... 16 2.6 Inclusion and exclusion criteria... 17 2.7 Data collection, instruments and materials... 17 2.7.1 Habits... 18 2.7.2 Functional interferences... 18 2.7.3 Mechanical interferences... 18 2.7.4 Dental development... 18 2.7.5 Maxillary permanent central incisors... 19 2.7.6 Maxillary lateral incisors... 20 2.7.7 Mandibular incisors... 20 2.7.8 Canines... 20 2.7.9 Posterior teeth... 21 2.7.10 Restorations and untreated gross interproximal caries... 21 2.7.11 Need for interceptive orthodontic treatment... 21 2.8 Data Processing and Analysis... 21 CHAPTER 3: RESULTS... 23 3.1 Demographics... 23 3.2 Habits... 24 3.3 Interferences... 25 3.4 Dental development... 26 3.5 Interceptive orthodontic treatment need... 33 CHAPTER 4: DISCUSSION... 34 4.1 Demographics... 34 4.2 Habits... 34 viii

4.3 Interferences... 35 4.4 Dental development... 36 4.5 Interceptive orthodontic treatment need... 40 4.6 Limitations of the study... 40 CHAPTER 5: CONCLUSION AND RECOMMENDATIONS... 42 REFERENCES... 43 ix

List of tables Table 3.2.1 Habits present 24 Table 3.4.1 Gender distribution versus premature canines 27 Table 3.4.2 Eruption pattern of incisors 28 Table 3.4.3 Alignment of anterior teeth 29 Table 3.4.4 Dental crossbites 30 x

List of figures Figure 3.1.1 Children examined at dental clinics 23 Figure 3.1.2 Gender distribution at both clinics 23 Figure 3.1.3 Age distribution at clinics 24 Figure 3.3.1 Functional interferences 25 Figure 3.3.2 Mechanical interferences 25 Figure 3.4.1 Dental versus chronological age 26 Figure 3.4.2 Gender distribution versus accelerated growth 26 Figure 3.4.3 Early loss of primary canines 27 Figure 3.4.4 Mobility of primary teeth 28 Figure 3.4.5 Presence of midline diastemas 29 Figure 3.4.6 Age distribution versus absent midline diastema 30 Figure 3.4.7 Untreated gross interproximal caries 31 Figure 3.4.8 Early loss of posterior teeth 31 Figure 3.4.9 Early loss of primary canines versus early loss of posterior teeth 32 Figure 3.4.10 Distribution of molar relationships 32 Figure 3.5.1 Interceptive orthodontic treatment need 33 xi

List of abbreviations DAI: DOH: TMJ: TOHC: Dental Aesthetic Index Department of Health Tempero-mandibular joint Tygerberg Oral Health Centre xii

List of addenda Appendix A: Written informed consent 50 Appendix B: Data capture sheet 53 xiii

CHAPTER 1: INTRODUCTION The majority of dentists only assess patients for orthodontic treatment when the patient presents with all their permanent teeth. Most of the government dental facilities are not able to provide interceptive orthodontic treatment and referrals are made to tertiary dental hospitals. As a result the waiting list for fixed orthodontic treatment at the Tygerberg Oral Health Centre (TOHC) is extremely long and increasing yearly. In 2007, the waiting list consisted of 24 patients, but by the end of 2011 it had reached a total of 1610. This is indicative of the urgent need for complex orthodontic treatment which is too extensive for the facility to cope with and a large financial burden is placed on the government to treat these patients. Interceptive and preventive orthodontic treatment should be regarded as a primary health care service, as it is less expensive than fixed orthodontic treatment. The goal of early interceptive orthodontics should be to help prevent the progression of permanent soft tissue or bony changes (Joondeph, 1993). It also promotes better oral health care and decreases the risk of dental caries as a result of malocclusion (Kerosuo, 2002). Previous studies done to determine the orthodontic treatment need mainly focused on children 12 years of age and older (Van Wyk and Drummond, 2005; Hlongwa and du Plessis, 2005). However, this age is beyond the realm of preventive and interceptive orthodontics (Kerosuo, 2002; King and Brudvik, 2010). During the mixed dentition stage, earlier intervention is possible, resulting in reduced costs for the patient and the health system (King and Brudvik, 2010). The psychological influence that malocclusion could have on the patient would also be addressed at an earlier stage (Kerosuo, 2002; King and Brudvik, 2010). This study seeks to determine the need for interceptive orthodontic treatment among 7-to-10 year old children at two clinics in the Tygerberg sub-district. 1

LITERATURE REVIEW 1.1 Definitions Preventative orthodontics refers to those measures taken to maintain the integrity of the normal developing dentition. These measures taken may include dietary counselling, dental prophylactic and conservative treatment and monitoring of the developing dentition (Hudson, personal communication, 2012). Interceptive orthodontics refers to simple orthodontic measures taken in order to correct developing problems so that, once corrected, normal development and growth can continue (Hudson, personal communication, 2012). Many of the procedures are common in preventive and interceptive orthodontics, but the timings are different (Hudson, personal communication, 2012). 1.2 Orthodontic treatment need: studies within South Africa Van Wyk and Drummond (2005) determined the prevalence of malocclusion and the relationship between certain socio-demographic elements among 12-year-old South African school children using the Dental Aesthetic Index (DAI). The study demonstrated that there is a high prevalence of malocclusion among 12- year-old children in South Africa. These include: 47.7% with minor malocclusion 52.3% with identifiable malocclusion o 21.2% of them presented with clear-cut malocclusion o 14.1% with severe malocclusion and o 16.9 % with extreme malocclusion. Hlongwa and du Plessis (2005) demonstrated that the need for orthodontic treatment among 12-year-old South African children in Mankweng, Limpopo was high. The results indicated that: 47% of the sample needed orthodontic treatment. Of these: 20% had a definitive malocclusion 13% had a severe malocclusion and 14% had a handicapping malocclusion. 2

de Mûelenaere (1997) conducted a study to investigate the possibilities for prevention of malocclusions in the mixed dentition stage of South African children. The first set of examinations was done on 951, 8-to-9-year-old children from 9 primary schools in Pretoria. Approximately 67% of them presented with Class I malocclusions. Anterior open bites with specific contributing factors occurred in 27.8%. After 2 years, only 493 children were re-examined. It was found that: In 12.1% of the 493 children, an acceptable occlusion had developed between the 1 st and 2 nd visits. Malocclusion was noted in 97% of the sample. 32.4% of the children received orthodontic treatment between the two visits. 3.3% of these were treated at government facilities. In 64.6% of the subjects, the malocclusion was not identified or addressed. The need for interceptive orthodontic treatment is controversial and two schools of thought exist: for and against early intervention (Mirabelli, 2005; Patti and D Arc, 2005). Comprehensive treatment might still be needed after interceptive orthodontic treatment (Jolley, 2010). The opposing group feels that it is better to start treatment when the permanent second molars and premolars have fully erupted, so that the treatment does not exceed 2 to 3 years (Patti and D Arc, 2005, Proffit, 2013). Proffit (2006) stated that it is vital to consider two aspects when one wants to determine the optimal timing for orthodontic treatment. These include effectiveness and efficiency. According to these principles, the gold standard for orthodontic timing is during the adolescent growth spurt, beginning in the late mixed or early permanent dentition (Proffit, 2006). Interceptive orthodontic treatment has been shown to be beneficial in decreasing the severity of malocclusion, improving self-confidence, removing detrimental habits, facilitating normal tooth eruption and improving some skeletal growth problems (Kerosuo 2002; King and Brudvik, 2010). Therefore the primary goal is 3

to eradicate or minimize dentoalveolar and skeletal disorders which are obstructing growth, function, aesthetics and the psychological welfare of children (Patti and D Arc, 2005; King and Brudvik, 2010). If treatment is not carried out during the mixed dentition stage and it is postponed until all the permanent teeth have erupted, more problems can arise and fixed orthodontic treatment will most likely be needed. Problems may include failure to modify skeletal growth problems or break detrimental habits (Kerosuo 2002; Patti and D Arc, 2005; Proffit, 2006; King and Brudvik, 2010). The ability to guide dento-alveolar development would also be lost (Kerosuo, 2002; Patti and D Arc, 2005; Proffit, 2006; King and Brudvik, 2010). Treatment would then often entail dental extractions and the need for difficult and complex appliances that could be detrimental to the health of the teeth and adjacent tissues (Patti and D Arc, 2005). Interceptive orthodontic treatment is a simple, beneficial method that should not cause strain on the co-operation of young patients (Patti and D Arc, 2005). It is important to establish what the cause of malocclusion is, before deciding on a treatment plan (Proffit, 2013). According to the literature, there are many classification systems available to determine the possible causes of malocclusion. These include classifications by White and Gardiners, Salzmann, Moyers and Graber (Singh, 2007). Moyers classification includes the craniofacial skeleton, dentition, orofacial musculature and soft tissues of the masticatory system. According to him, there are many contributing factors (genetic and environmental) and these often appear in clusters (Singh, 2007). 1.3 Normal dental development The change from the primary to the permanent dentition starts at the dental age of 6 years and ends at a dental age of 12 years (Proffit, 2013). It consists of 3 stages which include the first transitional stage, inter-transitional stage and second transitional stage (Bhalajhi, 2004; Rao, 2008). 4

The first transitional stage This period is seen between dental ages of 6 and 8 years. It is characterized by the eruption of the first permanent molars and the exchange of the primary incisors with the permanent incisors (Rao, 2008; Proffit, 2013). Dental age of 6 years: The flush terminal plane of the primary second molars will guide the permanent molars to erupt in an edge-to-edge relationship in almost 75% of all children (Patti and D Arc, 2005; Proffit, 2013; Hudson, personal communication, 2012). Once the first permanent molars have erupted, the permanent mandibular incisors erupt (Proffit, 2013). Dental age of 7 years: The maxillary central incisors and mandibular lateral incisors erupt one year after the mandibular central incisors have erupted (Proffit, 2013). Dental age of 8 years: The maxillary lateral incisors erupt and all the permanent incisors are present. There is a delay of 2 to 3 years before any further teeth appear (Proffit, 2013). The inter-transitional stage Dental age of 9 years: This mixed dentition phase is relatively stable with no active tooth eruption (Patti and D Arc, 2005; Rao, 2008). It is also known as the ugly duckling stage with midline diastemas that develop (Patti and D Arc, 2005; Rao, 2008) and both the upper and lower permanent canine bulges should be palpable (Hudson et al., 2010; Hudson et al., 2011). Dental age 10: Here, it is important to monitor the amount of resorption of the primary canines and molars as well as the root development of their permanent successors (Proffit, 2013). The second-transitional stage This stage is seen between the dental ages of 10-to-12 years and it is characterized by the replacement of the primary molars and canines with the premolars and 5

permanent canines (Rao, 2008). The permanent molars will drift mesially into a normal Class I relationship utilizing the leeway space (Patti and D Arc, 2005). Dental age 11 is characterized by the eruption of the mandibular canines, mandibular first premolars and the maxillary first premolars, which erupt almost at the same time (Proffit, 2013). Dental age 12: All the remaining succedaneous permanent teeth erupt (Proffit, 2013). 1.4 Molar relationship Angle classifies the first permanent molar relationships as cited by Proffit (2013) into a Class I, Class II or Class III relationship. A Class I molar relationship is seen as a favourable (normal) relationship in only a small (14%) percentage of children in the mixed dentition stage (Patti and D Arc, 2005). It is present when the mesio-buccal cusp of the upper first permanent molar occludes in the buccal groove of the lower first permanent molar (Proffit, 2013). A Class II molar relationship is seen as unfavourable and is present when the buccal cusp of the upper first permanent molar is positioned anteriorly (more than half a cusp size) with regards to the buccal groove of the lower first permanent molar (Proffit, 2013). A cusp-to-cusp Class II molar relationship is considered normal during the mixed dentition stage of development. Almost three quarters of children present with this molar relationship in the mixed dentition (Patti and D Arc, 2005). This is clinically identified when the buccal cusp tips of the first permanent molars coincide in the same vertical plane (Proffit, 2013). A class III molar relationship is seen when the buccal cusp of the upper first permanent molar is posteriorly placed (more than half a cusp size) with regards to the buccal groove of the lower first permanent molar (Proffit, 2013). 6

1.5 Dental manifestations that can be addressed with interceptive orthodontic treatment 1.5.1 Habits Genetic and environmental influences are the most important factors causing malocclusion (Yamaguchi and Sueishi, 2003). Abnormal oral functions which are also known as detrimental oral habits are defined as behaviours that interfere with the child s physical, emotional or social well-being (Rao, 2008). Habits mostly include thumbsucking, tongue thrusting, nail and pencil biting (Proffit, 2013), tongue biting, mouthbreathing and chewing unilaterally (Yamaguchi and Sueishi, 2003). With a digit sucking habit the position of the finger and tongue can also aggregate the problem (Flemming, 2008). During thumbsucking, the tongue is kept in a lower position away from the palate which can lead to narrowing of the maxilla (Flemming, 2008). It is important to establish the age of the patient and if the habit might be considered normal for example thumbsucking at the age of 3 years (Proffit, 2013). The possible cause, frequency, intensity and duration of the habit are important factors that need to be determined (Rao, 2008; Proffit, 2013). There are many possible causes related to abnormal habits, but some include psychological or genetic factors, nervousness, stress, lonesomeness, or idleness (Tanaka et al., 2008). It is important to try conservative methods before resorting to orthodontic appliances for treatment of habits (Rao, 2008). Discussions should be held with the child and parents and habit reminders such as a bitter substance or nail polish applied to the thumb could be used (Rao, 2008). If a malocclusion resulting from thumbsucking is present in the late mixed dentition or early permanent stage, it usually does not self-correct and interceptive orthodontic treatment is necessary (Stojanović, 2007). Even if thumbsucking during the mixed dentition stage has not resulted in the development of a malocclusion, if left to continue into the permanent dentition, chances that a malocclusion will develop are high (Singh et al., 2008; Urzal et al., 2013). 7

Since the 1960 s, Moss (1968) has theorized and demonstrated that growth of the skeletal bones are also influenced by other mechanisms, known as the functional matrix theory. For instance, the growth of the mandible does not primarily occur at the condyles, but is mainly due to normal function at the matrices of the developing teeth, muscles and soft tissues (Moss, 1997; Proffit, 2013). The Moss theory therefore implies that if abnormal functions are present and interference takes place at the functional matrices, normal growth and development of the jaws would be detrimentally affected (Moss, 1997; Proffit, 2013). The result could be malocclusion and or skeletal problems (Moss, 1997; Proffit, 2013). Malocclusions associated with digit sucking can include anterior open bites, proclined anterior teeth, increased overjet (Flemming, 2008; Mtaya et al., 2009), retroclined mandibular teeth, a retruded mandible or narrow maxilla, TMJ (tempero-mandibular joint) problems, central diastemas, (Singh et al., 2008) and posterior crossbites (Kennedy and Osepchook, 2005; Flemming, 2008; Proffit, 2013). Habits could cause a rippling effect in the further development of malocclusion, for example, the related anterior open bite could interfere and further affect the facial growth direction of the patient (Patti and D Arc, 2005). A simple anterior open bite is present from canine to canine and it is usually associated with a tongue thrust (Urzal et al. 2013), which maintains the anterior seal (Proffit, 2013). Possible aetiological factors for a simple anterior open bite include thumbsucking, lower lip biting and mouth breathing (Urzal et al., 2013). A simple tongue thrust is defined when the tongue makes contact with any teeth anterior to the molars during swallowing (Dixit and Shetty, 2013). Stojanović (2007) suggested that a tongue thrust either causes an anterior open bite, or it develops secondary to thumbsucking. A strong association was found between speech problems among children with a tongue thrust and anterior open bite (Khinda and Grewal, 1999; Dixit and Shetty, 2013). Detrimental habits do not only affect the occlusion, but it also negatively impacts the oral health related quality of life which includes oral symptoms like 8

gag reflexes, difficulty in chewing, emotional and social well-being (Leme et al., 2013). 1.5.2 Interferences The functional matrix theory also applies to interferences. As normal function leads to normal form, interferences can negatively affect the facial growth pattern (Moss 1997). Interferences can be classified as functional or mechanical. Functional interferences include mouthbreathing, tongue thrust (complex open bite) and lip wedging. Mechanical interferences include a Pseudo Class III, functional crossbites and deep bites (Patti and D Arc, 2005; Proffit, 2013). 1.5.2.1 Functional interferences It is well documented that untreated mouthbreathing during childhood could have a negative impact on dental and facial development (Bresolin et al., 1983; Principato, 1991; Faria et al., 2002 and Harari et al., 2010). This may include over-eruption of the molars, increased facial height, a higher palatal plane (Faria et al., 2002), increased overjet (Harari et al., 2010) and posterior crossbites (Kennedy and Osepchook, 2005). It may also result in the overdevelopment of the facial sinus with a disruption in air flow and an underdeveloped, narrow, V- shaped maxilla (Patti and D Arc, 2005). Mahony et al (2004) demonstrated in a longitudinal study that if the adenoids in children suffering from chronic mouthbreathing are timeously removed during childhood, it can significantly reduce the risk of developing dental and skeletal problems. Another problem with mouthbreathing in children is the risk of the tongue obstructing the airway and causing sleep apnoea (Defabjanis, 2003). This may result in sleepless and restlessness nights and ultimately in increased morbidity (Defabjanis, 2003). It is therefore vital that mouthbreathing be identified and treated as early as possible to ensure that normal development can take place. 9

Lip wedging is noted when the lower lip is positioned palatally of the upper incisors. If present during swallowing, it may cause the maxillary incisors to protrude (Patti and D Arc, 2005). Lip wedging can become a functional interference which may aggravate a Class II malocclusion that could have normalised during growth (Florman et al., 2008). It is therefore important to treat it early, especially among children with an increased overjet. 1.5.2.2 Mechanical interferences A mechanical interference refers to any dental interference (premature contact) that causes the mandible to slide laterally or anteriorly (Patti and D Arc, 2005). It is commonly found in the early mixed dentition and mostly involves the maxillary lateral or central incisors that are positioned in linguoversion (McIntyre, 2004). Any dental interference that causes the mandible to assume a position of convenience will have an effect on growth, if it is left untreated (Patti and D Arc, 2005). A primary interference is seen as an interference caused by a primary tooth and a secondary interference is when the permanent tooth is causing the interference (Patti and D Arc, 2005). Midlines should be examined for any deviations, left or right, and one should also look for the presence of an anterior or posterior crossbite. These include looking at the maxillary midline in relation to the midsagittal plane (Proffit, 2013). The second step is to look at the mandibular midline in centric relation and then in centric occlusion, compared to the midsagittal plane (Proffit, 2013). If there is a mandibular shift in centric occlusion, left or right, and the midlines coincide with the midsagittal plane in centric relation, a mechanical interference is present (Patti and D Arc, 2005). If there is an anterior slide, a Pseudo Class III exists (Rabie and Gu, 2000a). In cases displaying a lateral slide with a unilateral crossbite, a functional cross bite is noted (Proffit, 2013). Pseudo Class III cases can have detrimental effects on the dental and skeletal growth of the patient (Patti and D Arc, 2005; Proffit, 2013). The dental effects include retroclined upper incisors, proclined lower incisors, decreased mid-facial height and a retrusive upper lip (Rabie and Gu, 2000a). A 10

true skeletal Class III can develop as a result of compensatory growth in the condyles (Patti and D Arc 2005). Positive treatment outcomes have been shown when children with a Pseudo Class III are treated early in the mixed dentition phase (Rabie and Gu, 2000b). These include reduced mandibular displacement and creation of sufficient space for the other permanent teeth to erupt (Rabie and Gu, 2000b). It is therefore vitally important to treat a Pseudo Class III patient as early as possible, because if it is left untreated, it can lead to the development of a true skeletal Class III (Yelampalli, 2012). A functional crossbite is often due to maxillary narrowing (Wong et al., 2011). If left untreated, facial asymmetry (Pinto et al., 2001) and TMJ problems (de Boer and Steenks, 1997) could develop. This could either be due to asymmetrical condylar growth or as a result of the patient sliding the jaw continually to one side (Pinto et al., 2001). Thus early treatment is essential in order for normal function to occur (Cláudia et al., 2011). The patient should also be examined for the presence of soft tissue impingement and a deep bite (Proffit, 2013). In the mixed dentition stage, the overbite and overjet may increase as the permanent incisors erupt (Keski-Nisula et al., 2003). It is therefore normal to have a slightly deeper bite at this stage (Patti and D Arc, 2005). However, a deep bite becomes significant when it is equal to or more than 3.5mm (Tausche et al., 2004). A deep bite of 5mm or more is regarded as severe (Proffit, 2013). In these cases it is very likely that the deep bite will persist into the permanent dentition (Patti and D Arc, 2005; Proffit 2013). A deep bite can either be related to a skeletal or dental cause (Proffit 2013; Singla et al. 2013). Infra-occlusion, unerupted posterior teeth, early loss of teeth and over-eruption of the anterior teeth can also lead to the development of a deep bite (Proffit 2013; Singla et al. 2013). 11

Detrimental effects of a deep bite include TMJ problems (Darendeliler et al., 2004), attrition of the anterior teeth, trauma and periodontal problems of the palatal gingiva of the upper incisors or the labial gingiva of the lower incisors (Singla et al., 2013). A deep bite could also restrict the anterior development of the mandibular dento-alveolar process. This is difficult to treat later in life (Patti and D Arc, 2005). It is therefore vital that a deep bite related to dental causes be treated as soon as possible to prevent further problems. However, if it is the result of a skeletal problem, treatment becomes more complex and the condition is rarely treated within the mixed dentition stage (Proffit, 2013). 1.5.3 Problems hampering normal dental development 1.5.3.1. Poor oral hygiene Good oral hygiene is very important prior to the commencement of orthodontic treatment (Proffit, 2013). Signs of gingivitis and the presence of plaque on the teeth (Cameron and Widmer, 2008) should be noted. 1.5.3.2. Dental caries and early loss of primary teeth All the teeth present should be examined for the presence of decalcifications, attrition, and dental caries (Cameron and Widmer, 2008). Severely carious teeth can affect the quality of life (Low et al., 1999), by causing pain and abscess formation and loss of sleep and it may become life threatening if left untreated (Cameron and Widmer, 2008). Any carious lesions should be treated before orthodontic treatment is started (Proffit, 2013). Untreated dental caries of primary teeth in the mixed dentition which affect the pulp can lead to dental extractions (Cameron and Widmer, 2008). This may result in shortening of the dental arch (Kerosuo, 2002) of up to 4mm (Hudson et al., 2013). If the mandibular primary canines are lost early, it can cause anterior collapse of the mandibular arch with subsequent collapse of the maxillary arch (Hudson et al., 2011). This may cause crowding in the permanent dentition (Kerosuo, 2002; 12

Laing et al., 2009), ectopic eruption (Flemming, 2008), impactions, crossbite formation and a midline shift (Laing et al., 2009). Early loss of the second primary molar could result in a mesial drift of the permanent molar and it may either cause a Class II or III molar relationship (Rao, 2008). 1.5.3.3 Dental and chronological age It is important to compare the dental and chronological age of a patient (Proffit, 2013). Small variations in the timing of eruption are considered normal (Proffit, 2013). However, changes in the sequence of eruption, delayed and asymmetrical eruption of teeth needs further examination (Patti and D Arc, 2005; Proffit, 2013). 1.5.3.4 Unfavourable sequence of eruption If one of the maxillary central incisors has been unerupted for 6 months or longer, but the contralateral tooth is fully erupted or if maxillary lateral incisors have erupted before the central incisors, it could be indicative of a dental problem (Patti and D Arc, 2005; Proffit, 2013). These problems could have a negative impact on the normal development of occlusion (Patti and D Arc, 2005; Proffit, 2013). 1.5.3.5. Canine ectopia Buccal canine bulges should be palpated bucally with a finger to assess whether they are present or not (Proffit, 2013). The maxillary and mandibular canine bulges should be palpable at 9 years of age and its absence could indicate canine ectopia (Resh, 2005; Hudson et al., 2010; Hudson et al., 2011). It is therefore important that all children between the ages of 9 and 11 years be examined for canine bulges (Resh, 2005). Absence of these bulges warrants further investigation and radiographs should be taken (Shapira and Kuftinec, 1998). There are many possible co-inciding factors related to canine ectopia, including peg laterals, infra-occlusion of primary molars and rotated lateral incisors (Bacetti 1998). Other factors include retained primary teeth, enamel hypoplasia, ectopic eruption of the first permanent molars and dental malformations like taurodontism and dens invaginatis (Hudson et al., 2010). If the maxillary primary canines are still present and immobile at the ages of 12 or 13 years, it could be a sign that the permanent successors are impacted (Hudson et al., 2010). 13

1.5.3.6. Asymmetrical mobility The presence of symmetrical mobility for the same contralateral primary tooth is very important for normal dental development. If both teeth are not mobile within 6 months of each other, asymmetrical mobility is present (Proffit, 2013). Asymmetrical mobility may lead to the loss of leeway space and drifting of the teeth with a resultant midline shift (Proffit, 2013). 1.5.3.7. Bruxism Generalized attrition of the teeth could be a sign of bruxism at night (Cameron and Widmer, 2008). This should be discussed with the parent and a night guard could possibly be introduced to prevent further damage to the teeth (Proffit, 2013). 1.5.3.8. Hyperactive frenum It is important that the frenulae of both the maxilla and the mandible be examined (Proffit, 2013). If blanching is noted in the attached gingiva between the central incisors, an active frenum is present (Proffit, 2013). A hyperactive frenum could result in a midline diastema and gingival recession (Delli et al., 2013). 1.5.3.9. Rotated lateral incisors The mandibular lateral incisor is found to be the most commonly rotated tooth in the mandible (Shapira and Kuftinec, 2002). Lateral incisors that are lingually displaced are not able to direct the permanent canines to erupt into the correct position (Hudson et al., 2010). This leads to the mesial eruption of the permanent canines, overlapping of the lateral incisors, further loss of space and resultant crowding (Hudson et al., 2010). 1.5.4 Skeletal discrepancies According to Proffit (2013), it is important to carefully examine the profile for facial and skeletal discrepancies that may be visible in an antero-posterior and vertical dimension. This is also regarded as the poor man s cephalometric analysis as it may provide some information, though in less detail, when compared to the analysis of lateral cephalometric radiographs (Proffit, 2013). 14

Whenever a jaw irregularity is found, it is best to correct it by modifying the growth so that the skeletal problem may disappear as the child grows (Patti and D Arc, 2005; Proffit, 2013). The mixed dentition stage, just before puberty, is regarded as the time where most of the growth takes place and it is the ideal time to modify the growth (Patti and D Arc, 2005; Proffit, 2013). It is therefore vital to ensure a correct diagnosis and treatment plan to allow normal growth to take place and minimize the need for complex dental and skeletal therapy. 15

CHAPTER 2: MATERIALS AND METHODS 2.1 Aims The aim of the study is to investigate the need for interceptive orthodontic treatment among 7-to-10-year-old children attending dental clinics in the Tygerberg sub-district. 2.2 Objectives 1. To determine the prevalence of malocclusion among 7-to-10-year-old children examined at the dental clinics within the Tygerberg sub-district. 2. To determine the types of malocclusion they present with. 3. To determine which of the malocclusions present in the sample of patients can be treated with interceptive orthodontic treatment. 2.3 Ethics Ethics approval, (reference number: 12/7/17), was obtained from the Research Committee of the Dentistry Faculty as well as the Senate Higher Degrees Committee of the University of the Western Cape. 2.4 Study sample. Permission was sought from the Department of Health (DOH) Western Cape in order to include five Government dental clinics within the Tygerberg sub-district in the study. These clinics included Bishop Lavis, Elsies River, Goodwood, Bellville and Delft. Unfortunately, clearance was only obtained for three clinics, namely, Bishop Lavis, Goodwood and Bellville. Goodwood was then excluded from the study sample as no children are treated at that dental clinic. Children between the ages of 7 and 10 years were included in the study. Random dates were chosen and examinations took place on these days. Permission to visit each clinic was sought in advance. Each clinic was visited at least 5 times. As determined by a statistician, a hundred children were included in the study. 2.5 Research design An analytical, descriptive, cross-sectional study was carried out and quantitative methods were used to achieve the aim and objectives. 16

2.6 Inclusion and exclusion criteria All children between the ages of 7 and 10 years presenting at the clinics on the day of research visit were invited to participate in the study. Dental examinations were conducted on these children and their last birthday was taken as their existing age. Children younger than 7 years and above 10 years of age were excluded from the study, but no child was refused a consultation. Participation in the study was entirely voluntary and refusal to participate did in no way disadvantage the patients. Written informed consent (Appendix A) was obtained from parents who attended the dental clinics with their children. In cases where the children were sent from a school, consent forms either signed by the parents or the principal of the school were brought by the children attending the dental clinic. All parents were advised as to the nature of the treatment their child needed and referred to the relevant facilities for treatment where necessary. 2.7 Data collection, instruments and materials Clinical data was collected using a prescribed form (Appendix B). The names and personal details of all the participants and their families were kept confidential at all times. All completed questionnaires and signed informed consent forms were placed into two separate boxes by the participants themselves and the names of the subjects were not mentioned on the data capture sheets. The boxes were sealed and only opened when all data had been collected. It was only handled by the examiner herself. The informed consent forms, and data capture sheets will be kept in a locked cabinet (that only the examiner has access to) for a minimum period of three years. Each intra-oral examination was done using gloves, a wooden tongue depressor and a disposable transparent ruler. The examination lasted approximately 10 minutes and was conducted prior to the children receiving dental treatment from the operating dentists. 17

2.7.1 Habits The parent and /or child was asked if the thumbsucking habit was present. The age until which this habit persisted was recorded where necessary. The child was considered to be a thumbsucker if he / she was still thumbsucking after the age of 4 years. The presence of other habits like pencil biting, nail biting, dummy or biting the lower lip was also recorded. A simple tongue thrust was associated with an anterior open bite from canine to canine which could be related to thumbsucking. 2.7.2 Functional interferences The mother and /or child was asked if he / she constantly breathed through the mouth during the day or night. If the habit was present, it was determined whether mouthbreathing was due to allergies (seasonal) or if it persisted for a long period of time (obstructive). On examination, the extent of the open bite was assessed. Open bites extending beyond the canines, were associated with a complex tongue thrust. Lip wedging was noted when the mentalis action was present in association with a large overjet. 2.7.3 Mechanical interferences Mechanical interferences (Pseudo Class III, functional crossbites and deep bites) were examined as defined in chapter 1.The overbite was measured by assessing the amount of overlap between the mandibular and maxillary central incisors. A deep bite was regarded as 3.5 mm or more and the reading in millimetres was recorded. 2.7.4 Dental development Please refer to the chapter 1 with regards to dental development and related dental age. 18

Normal dental development was noted when the dental age corresponded with the chronological age. Accelerated dental development was regarded when the dental age was ahead of the chronological age. If dental age was delayed when compared with chronological age, it was regarded as delayed dental development. The mobility of the primary teeth was examined and teeth that were near exfoliation were noted. If equal mobility was noted in the contralateral tooth, it was regarded as being symmetrically mobile. If only one tooth was mobile or had recently exfoliated and the other tooth was not, asymmetrical mobility was noted. Retained teeth were seen when the teeth were still present in the mouth, but according to the dental age, should have exfoliated. Only erupted supernumery teeth could be diagnosed as no radiographs were available. 2.7.5 Maxillary permanent central incisors During examination, the presence of erupted maxillary central incisors was evaluated. Delayed eruption of one or both of the maxillary central incisors was noted when they were absent at the age of 7 years. Midline diastemas and dental age are discussed in chapter 1. Diastemas larger than 2 mm were noted as enlarged. The absence of an expected midline diastema at 9 years of age was noted, as it can play a role in the canine development. The presence of an active frenum was examined, by pulling the upper and lower lips away from the teeth. If blanching was noted in the attached gingiva between the central incisors, an active frenum was recorded. If blanching was absent, it was considered normal. If one or both maxillary central incisors were lingually positioned with regards to the lower incisors, a crossbite was noted. The position of both the maxillary central incisors was viewed in relation to the other anterior teeth. A rotation was 19

present if one (or more) central incisors had distal or mesial aspects that were displaced relative to the shape of the dental arch. 2.7.6 Maxillary lateral incisors The different dental ages are discussed in chapter 1. When the maxillary lateral incisors were missing after the age of 8 years, the tooth was considered absent. It was difficult to know if they were delayed, congenitally missing or had possibly been extracted as no radiographs were available. During examination, the size and shape of both the maxillary lateral incisors in relation to the maxillary central incisors were evaluated. In cases where the lateral incisors had an unusually small size and shape, it was considered to be a peg lateral; otherwise it was considered normal. The position of both the maxillary lateral incisors in relation to the other anterior teeth was examined for rotations. In cases where one or both of the maxillary lateral incisors were lingually positioned with regards to the lower incisors, a crossbite was noted. 2.7.7 Mandibular incisors The alignment and crowding of the mandibular incisors were examined. If they were well-aligned, it was regarded as normal ; otherwise it was recorded as crowded. The lateral incisors were examined in relation to the mandibular central incisors and were either categorised as well-aligned, lingually placed or rotated. 2.7.8 Canines The presence of canines related to dental age is discussed in chapter 1. When the primary canines had been lost before the expected normal exfoliation time, early loss was noted. The presence of canine bulges in both arches was noted by palpating the areas where the canine bulges should be. All subjects were checked for buccal canine bulges. In cases where the buccal canine bulge was not palpable the canine was considered ectopic. 20

2.7.9 Posterior teeth The first permanent molar relationship was examined and noted under different categories. Either unable, (when one or both of the molars was missing) Class I, cusp-to-cusp ( end to end ), Class II, or Class III. In cases where the molar relationship was not a cusp-to-cusp Class II, it was considered to be an unfavourable molar relationship. If one or more primary molars were missing before the normal expected exfoliation age, the patient was considered to have had early loss of posterior teeth. When the buccal surface of the upper permanent posterior teeth occluded palatally in relation to the buccal surface of the lower permanent posterior teeth, a posterior crossbite was recorded either unilaterally or bilaterally. The occlusal plane of the primary molars was examined. Infra-occlusion was noted when a definitive step in the occlusal plane was present and the primary molar was not in line with the rest of the occlusion. 2.7.10 Restorations and untreated gross interproximal caries All tooth surfaces were examined for the presence of restorations and untreated gross interproximal caries. 2.7.11 Need for interceptive orthodontic treatment At the end of each examination, all the above-mentioned facts were considered. If one or more of the factors were present, the patient was considered to need interceptive orthodontic treatment. Patients requiring treatment were provided with a letter informing the parent of the child s treatment need, so that the patient could be assessed orthodontically. 2.8 Data Processing and Analysis Information recorded on the data capture sheets was transferred to an Excel spread sheet which contains no personal details. All the information was kept on a password protected computer, to which only the examiner had access. Only the 21

researcher and supervisors were eligible to view identifiable data. Anonymity was thus diligently preserved. The analyses of the results were done by a statistician using a program cited as the R Development Core Team (2012). R: A language and environment for statistical computing. R foundation for statistical Computing, Vienna, Austria. ISPN 3-900051-07-0. 22

CHAPTER 3: RESULTS 3.1 Demographics 49% 51% n=100 Bellville Bishop Lavis Figure 3.1.1 Children examined at dental clinics Percentage (%) 35 30 25 20 15 10 26 25 20 29 Bellville Bishop Lavis 5 0 n=100 Male Gender Female Figure 3.1.2 Gender distribution at both clinics 23

40 35 35 Percentage 30 25 20 15 22 17 26 10 5 0 n=100 7 8 9 10 Age (years) Figure 3.1.3 Age distribution at clinics 3.2 Habits Table 3.2.1 Habits present Habits Girls Boys Total (%) Thumbsucking 16% 5% 21% Tongue thrust (simple open bite) 9% 5% 14% Other habits: 19% 16% 35% Lower lip biting 1% 0% 1% Nail biting 12% 10% 22% Pencil biting 5% 6% 11% Pencil and nail biting 1% 0% 1% A significant relationship was found between gender and habits (Chi-squared test, p=0.04). 24

3.3 Interferences 30 25 25 26 Percentage (%) 20 15 10 5 0 n=52 Mouthbreathing 1 Tongue thrust (complex) Functional interferences Lip wedging Figure 3.3.1 Functional interferences Mouthbreathing was found to be 15% obstructive and 10% seasonal. Percentage (%) 20 18 16 14 12 10 8 6 4 2 0 n=36 18 13 5 Pseudo Class III Functional crossbite Deep bite Mechanical interferences Figure 3.3.2 Mechanical interferences A small percentage of (3%) of Pseudo Class III cases were due to primary interferences and 2% were due to secondary interferences. 25

3.4 Dental development 60 Percentage (%) 50 40 30 20 48 13 39 10 0 n=100 Normal Delayed Accelerated Dental age Figure 3.4.1 Dental versus chronological age 30.80% 69.20% n=100 Female Male Figure 3.4.2 Gender distribution versus accelerated growth A statistically significant relationship (Chi-squared Test, p= 0.0145), was found between gender and accelerated dental age. 26

Table 3.4.1 Gender distribution versus premature canines present Age (years) Girls Boys Total (%) 7 0% 0% 0% 8 3% 0% 3% 9 10% 0% 10% 10 13% 8% 21% Total 26% 8% 34% A statistically significant relationship, was found between gender and premature canines present (Chi-squared Test, p= 0.0012). 25 20 20 Percentage (%) 15 10 5 5 5 14 0 n=44 7 8 9 10 Age (years) Figure 3.4.3 Early loss of primary canines 27

90 85 80 70 Percentage (%) 60 50 40 30 20 15 10 0 n=100 Symmetrical Mobility Assymetrical Figure 3.4.4 Mobility of primary teeth Retained primary teeth were present in 6% of cases and no infra-occlusion or supernumery permanent teeth or were noted. Table 3.4.2 Eruption pattern of incisors Percentage Maxillary central incisors: Normal 95.6% Delayed 4.4% Maxillary lateral incisors: Normal 72% Unerupted (age 7) 19% Unerupted (age 8) 6% Congenitally missing (age 9 and 10) 3% 28

Table 3.4.3 Alignment of anterior teeth Rotations present: Percentage Maxillary central incisors Normal 84.5% Rotated 15.4% Maxillary lateral incisors Normal 42.5% Rotated 57.5% Mandibular anterior crowding 38% Mandibular lateral incisors Normal 74.7% Lingually positioned 7.3% Rotated 18% 70 64 Percentage (%) 60 50 40 30 20 10 23 13 0 n=100 No Yes N/A Absent midline diastema Figure 3.4.5 Presence of midline diastemas 29

30 28 25 Percentage (%) 20 15 10 7 10 19 5 0 n=64 7 8 9 10 Age (years) Figure 3.4.6 Age distribution versus absent midline diastemas Only 1% of the sample presented with an active frenum. Table 3.4.4 Dental crossbites Percentage Total Anterior crossbites 16% Maxillary central incisors 4% Maxillary lateral incisors 12% Posterior crossbites 17% 30

10% 90% n=100 Present Absent Figure 3.4.7 Untreated gross interproximal caries Only 5% of the sample received restorations or fissure sealants. 25 23 Percentage (%) 20 15 10 16 12 17 5 0 n=68 7 8 9 10 Age (years) Figure 3.4.8 Early loss of posterior teeth 31

Percentage (%) 100 90 80 70 60 50 40 30 20 10 0 86 54 Early loss of primary posterior teeth 14 Early loss of teeth 46 Primary posterior teeth present Early loss of primary canines Primary canines present Figure 3.4.9 Early loss of primary canines versus early loss of posterior teeth Overall loss of primary teeth were 71% and a highly statistically significant relationships between the early loss of primary canines and early loss of primary posterior teeth (Chi-squared test, p=0.0005). Percentage (%) 60 50 40 30 20 10 0 n=100 49 2 9 7 Class I Class II Cusp to cusp Class II Class III Molar relationship 33 Other (mixed) Figure 3.4.10 Distribution of molar relationships 32